1. Field of Invention
The present invention relates to a method, apparatus and system for making sulfuric acid, especially a method, apparatus and system capable of sufficiently recycling heat energy.
2. Description of Related Art
Sulfuric acid is a very important chemical compound and has extremely comprehensive industrial purposes. It not only may be used to manufacture fertilizers, non-alkaline detergent, skin care products, paint additives but also can be utilized to make explosives. Sulfuric acid plays the role of an essential material that many industries rely on, and the large market demand has been already reflected on the huge yield quantity. As a result, many local entrepreneurs in the world are attracted to invest on production of sulfuric acid. However, while each of the entrepreneurs smoothly mass-produces sulfuric acid, they still need to spend some efforts to keep on product improvement such that they can expect to increase efficiency of equipments, lower power consumption, reduce the manufacture cost, and then enhance economic benefit and competitiveness of enterprises.
Meanwhile, with advancement of technologies, not only traditional industries continue to develop, but also more and more innovative industries quickly grow up. When production capacities of these industries continuously expend, spent acid or waste acid is likely generated during manufacturing processes. For example, it needs to adopt extremely high purity sulfuric acid during cleaning semiconductors and add hydrogen peroxide solution in terms of a certain proportion to accelerate reaction speed and enhance cleaning effect. In such circumstance, the spent acid contains sulfuric acid and hydrogen peroxide. When the production capacities achieve to a certain level, the volume of generated waste sulfuric acid or waste acid will be quite enormous. The generated waste sulfuric acid or waste acid not only takes a portion of the manufacture cost but also needs adequate recycling through efforts of business entities to meet regulation requirements and prevent from contaminating the environment.
Therefore, it is very important to develop a method and apparatus for making sulfuric acid in order to not only produce sulfuric acid at high concentration, for satisfying the needs of industrial purposes and especially appropriate for reproducing high concentration sulfuric acid having economic value from recycled spent acid or waste acid, but also sufficiently recycle heat energy simultaneously, for lowering power consumption and then reducing the total manufacture cost.